To have a fair comparison, we also perform the SPDA [1]} and the channel shortening (CS) method as proposed in [2]}.
Furthermore, truncated-BCJR detection algorithm [3]} for FTN detection is also evaluated to demonstrate the accuracy of the analytical bound, i.e., (REF ) and (REF ), when a limited number of ISI taps is considered by the detection algorithm.
Note that, in order to improve the error perforamnce, the BCJR algorithm usually requires a terminated trellis [4]}.
Therefore, in our simulation, we intentionally transmit additional symbols to terminate the ISI trellis.
Specifically, four additional code symbols are transmitted for the BCJR decoder for CC, while \(2 \times L_E\)  additional symbols are transmitted for the truncated-BCJR algorithm.
The analytical BER of a specific code rate \(R\)  is summed over the CC minimum Hamming distance \(w = d_{\text{min}} = 5\)  to a Hamming error weight 8 and the approximate full-taps BERs consider \(L = 11\)  ISI responses.
